Fluid compressor



fl".` MANISCALCO FLUID ctmPREssoR.

Filed July- 17, 1940 sept. 23, 1941.

j Sept. 2 3, 1941. P. lvmNlsciALczo` l FLUID comREssoR l Filed July 17,1940 2 sheetsvsheet Patented Sept. 194,1

UNITED .STATES PATENT oFFlcE 2,256,926 FLUID coMrnEsson 'e riem Mmmm,chicago, n1.

Application .my 17, mo, serial No. 345,951; In Canada December fi,193i)- 2 exilim.4 (ci. 23o-200)' This invention relates to` an improvedfluid compressor, and more especially to a compressor unit of themultistage type;A

One of the objects of this invention is to provide a novel compactcompressor of a simplied and economical construction, capable ofspeedily 4producinga high stage of compression, the same beingpreferably accomplished by producing a two-stage compression with eachcomplete piston stroke, by the use of a primary and a secondary piston.

Another object of this invention is to provide a release or bypass forany back-pressure that may an etllcient compressor ofv this kind whichis especially adapted for usel with refrigeration and ai:I conditioningdevices.

These and various other objects and advandrawings wherein theinventlonlis illustrated in its preferred form, it being apparent thatvarious -ltages are attained with this invention, as will 'becomeapparent from the following description, -talren in connection with theaccompanying other arrangements and forms of construction may be adoptedfor carrying out purposes of this invention.

In the drawings:

Fig. 1 is aplsn viewof a compressor embodying the present invention inits preferred form of construction.

the objectsA and;

"Figs, 2 and 3 are enlarged vertical sectional views of the improvedcompressor, taken on lines 2-2 and 3 3, respectively.

The form of this invention disclosed herein i embodies a compact sealedcompressor unit,` which is shown as being of the multistage type.

It comprises a casing or housing including upstanding walls 6, 1, I andl which are integral with each other and are integral with the base I0wherefrom they arise, flanges or other suitable means II being providedon the base for' mounting the compressor on a suitable support. The twoopposite walls t and l have integral sleeves I2 and Il extending inopposite directions therefrom, providing cylinder chambers I2', Il' -f5bearing collarll which is-re/i/iovably mounted'- of a drive shaft 21.

therein. These cylinders have their longitudinal axes aligned, and thecylinder I2 is larger than the cylinder I3 and forms the primarycompression cylinder-,while the cylinder I3 forms the secondarycompression cylinder.

Closure members or cylinder heads I4 and I5 are removably mounted onVthe outer ends of cylindersl I2 and I3, respectively, being preferablythreaded thereon and supplied with a sealing gasket,v to provide a tightclosure. An inlet pipe It is connected to head Il, and an outletpipe Ilis connectedto head I5, check valves I8 and I8 being mounted in suitablepockets provided in heads Il and I5 to admit the passage of fluid inonly one direction, from pipe I6 to pipe II.-

The piston means herein is provided in the form of a piston unit 2Iwhich comprises at its.

opposite ends4 a larger primary piston 22 and a smaller secondary piston23, iltting snugly and operating in the cylinder chambers I2 and I3',respectively, and they are provided with suitable 'pistorrrings Saidpistons 22 and'23 contain in their ends pockets 24 and 25, respectively,having check valves 26. and 21 therein. A'bore 28 extends thru thepiston unit 2|", from pocket 2l to pocket 25, preferably extendingstraight along.

the longitudine1 axis of saidunit.v

Thisyarrangement of the cylinders and pistons provides a largercompression chamber I2', to eilect the primary compression, and fromwhich the fluid isforced thru the bore 28 into the secondary chamberIl', where itis then subjected to a higher stage of compression, and istherefrom delivered to outlet pipe I1 for use. This construction thusproduces a two-stage compression with each complete piston stroke.

The-means provided for driving or reciprocat' in g the piston unit 2l isof a compact form and has its essential operating .means or movablemembers housed Withimthe casing, the same comprising a reciprocatingmember 3| which is substantially cup-shaped and is secured to a flat'-tened side portion 32 of the intermediate part or body of piston unit2I,` by the use of screws or the like, as best shown in Fig; 2 of thedrawings;`v

while a companion rotary member I3 engages member 3l for reciprocatingthe same. Said member 2i includes a laterally extending pe'l ripheralflange 34 which provides a continuous. inner bearing surface or guidesurface 2l therein, vand over itA travels the rotaryvmember M the innerend which is. secured eccentrically on The drive shaft a1 is'rotatablymountea 1n a invwall 9 of the casing, preferably by threadingit in a threaded opening provided in wall 9, said wall being for thatpurpose made of considerable thickness. A stuiling nut 42 ls threaded onthe outer end of said collar and contains sealing rings 43 therein. -Theshaft extends beyond the nut and has a member thereon for driving it,for

allowing the air under pressure to pass freely upwardly around andoversaid marginal part i! up into channel BI.

Cooling fins 1I are preferably also provided to extend radially from thecylinders i2 and I3 and from the heads I4 and I5. to facilitate theready dissemination of heat away from this compressor.

The construction is simpleand durable and facilitates convenientinstalling and replacing of the mechanism in the casing. The piston unit2l is inserted thru the larger cylinder I3 and the reciprocating member3I is introduced thru `the open top and is secured to the part 32 of thepiston unit. 'I'he bearing collar 4I with its shaft is thus readilyinstalled and also detached. r

Other sealing means is likewise included wherever needed in order toprovide a iiuid tight casoperating parts or movable members of thecompressor; while improved means for distributing the lubricant mayfurthermore be provided,-

which preferably comprises one or more splash :fingers 54 extendingradially from the shaft within the casing, so as to lift and splash thelubricant upwardly over the operating members 33 and 34 and the bearings46, and. also over the pistons, especially when the lubricant is nolonger standing of suicient height to reach the bearings.

Chamfers or bevels 55 are provided in the' casing, on the joining edgeportions between the casing wall and its cylinder chamber I2', andbetween the casing wall 8 and its cylinder chamber i3', as shown in Fig.3. These chaxnfers are effective in draining off excessive lubricationon the pistons and to allow the same to flow back into the lower part ofthe casing. They serve to keep the lubrication on the pistons at aproper minimum amount, and they also aid in preventing lubricant fromgetting into the outlet pipe I1.

Provision is 'moreover made herein to take care of any compressed airthat may ieak from the cylinder chambers past the pistons into thecasing, and to provide a release for any back-pressure produced in thecasing during reciprocation of the two diierent sized pistons. For thispurpose a bypass is provided to receive any such compressed air that maybe present in the casing and to convey it from the casing to the inletconduit or the inlet head, and this bypass preferably comprises anescape channel 6I provided thru the cover 5I, and a pipe or conduit 62connected at one end to channel 5I, and at the other end to inlet pipeI6 adjacent head I4, having asleeve A deecting member 56. which issubstantially in the form of a baiile plate, ,is furthermore providedunderneath cover Si. It is shown detachably secured thereto by suitableelements 61, but it may also be cast integral therewith. Said plate isspaced from the cover by spacers 68, and it has its marginal portion i9curveddownward and spaced from the casing walls, in order to provide adeflecting marginal part for directing oil sprays 3l mounted therein andcarrying the reciprocating member 33 and splash ngers 54 is then securedin the wall 9 bringing member 33 in operative position in ilange means34; and the cover 5i with its deiiecting member 6B is secured on the topof the casing, thus sealing the casing air-tight and fluid-tight, whilethe bypass means is secured on the device as indicated above.

'I'his construction provides a compact compressor including a sealedcasing for retaining lubrieating means wherein the operating members ofthe compressor function, and for continuously lubricating the containedmovable parts. Furthermore, in case any compressed air leaks past eitherpiston into the casing, or any back-pressure results in the casing dueto the different sizes of the two pistons operating therein, then,assoon as such pressure is greater than atmospheric or than that ininlet pipe I6, then the bypass `will conduct such air from the casing tothe inlet pipe; and the spring of the spring-held valve 64 is also madeofthe proper tension to permit said valve to open when the airpressurein the casing is slightly higher than atmospheric or is at theparticular pressure intended.

I claim:

l. A compressor comprising a closed casing containing integral uprightwalls with an integral bottom thereon and an openable cover, twoopposite walls being provided with two opposltely extending cylinders, apiston unit in the casing including a pair of oppositely extendingpistons rcciprocable in said cylinders, valved closure means on the endsof the cylinders, operating means including a member detachablyconnected to the piston unit and a. drive shaft having a member thereonwhich engages the last said member for reciprocating it and the pistonunit, a bearing collar detachably mounted in an opening provided in oneof said walls and having the shaft journaled therein, said collar withthe drive shaft and the member thereon being readily removable andinsertable thru said wall opening, fluid conducting means to conductcompressed uid out -of the casing that may occur therein, and lubricantdeiiecting means 'mounted in the casing to prevent lubricant fromgetting inte said fluid conducting means.

2. A compact multmtage compressor which comprises a closed casingincluding integral upright walls and integral bottom thereon and anopenable cover, two opposite walls being provided .with a pair ofintegral outwardly extending cylinders, one being larger than the other,a closure head -wit-h an Vinlet valve on the larger cylinder and aclosure head with an outlet valve on the smaller cylinder, a piston unitin the casing including a body having a larger and a smaller pistonextending in opposite directions therefrom and being reciprocable insaid cylinders, a valved downward into the easing. and at the same timechannel centrally vthru the piston unit lproviding a passage from thelarger to the-smaller cylinder, operating means including areciprocating member having a continuous bearing ange and beingdetachably secured to said body, a rotary member engaging said memberand provided with a drive shaft extending from the casing, forreciprocating the piston unit, bypass means extending from Y the coverto conduct compressed uid lfrom the casing'ad :nto communication withthe met head on the larger cylinder, lubricant raising means provided onthe shaft, and lubricant deecting means between said raising means and 5said cover toprevent lubricant from entering the bypass. y a

PIETRO MANISCALCO.

